Undo problem

I'm working with various concert pitch scores, rearranging and transposing them for guitar and Bb saxophone, (soprano & tenor). I'm getting confused with the interaction between the 'concert pitch' button, the 'staff properties/change instrument' function and the 'transpose' function. Rather than flog though all the combinations and permutations I've got into a mess with, could I ask simply what is the best, (right?) way to transpose the attached opening bar of 'Once In A While' which is in concert Eb with the 'concert pitch' button activated in MS, to put the guitar in concert F and transpose the voice staff for Bb sax in G?

Thanks...